Brain and Mind

David A. Oakley

• Publisher: Taylor & Francis
• Year: 2018
• eBook ISBN: 9781351356817
• Edition: 1
• Topic: Psychology
• Subtopic: Cognitive Psychology & Cognition
• Index: Psychology

The relationship between brain and mind is one of the most baffling problems in science but potentially one of the most interesting. First published in 1985, this collection of original essays traces the development of mind in animals and human beings from its origins in the evolution of larger brains with a capacity for creating mental models of the environment. Examples are given of the way in which the brain may use this increased capacity to represent both the physical and social worlds, and the authors suggest that this type of mental activity might underly what human beings recognize in themselves as 'awareness' or 'consciousness'.

Brain and Mind brings together much of the latest research and provides a useful framework for the study of this increasingly important subject. The contributors are experts in a wide range of disciplines and draw their conclusions from a broad base of clinical and experimental evidence. Students of psychology, zoology, anatomy, medicine and philosophy, as well as anyone who has wondered about their own mind and its relation to the brain, will find this a fascinating and stimulating source.

1 On the evolution of mind

Harry J. Jerison

Most of us think of mind as a little person in the head, the ‘knower’ of reality (cf. Attneave, 1960). It is this intuition that will be elaborated for an evolutionary analysis of the place of mind in nature. Our major task, in this chapter, is to develop the intuition into an idea about the activity of an organ of the body, because evolutionary biology is about organic evolution, and the evolutionary biology of mind must be about the organic basis of mind.

The organ of mind is the brain, of course. The task, then, is to identify aspects of the brain that are correlated with its work as the organ of mind, and to describe the organic evolution of this brain/mind system. Most of the chapter is on this substantive problem.

Darwinism has traditionally been a doctrine about phyletic history, about the origin and change of species. As a doctrine it has been rooted in the similarities and differences among species and in the reconstruction of phyletic histories, of family trees and the bundles of related species (clades) that are the branches in a family tree. Yet in the evolution of behavior there is evidence of correlated advances in mental capacity across broad spectra of species. Progressive, or anagenetic, evolution is sometimes evident to comparable degrees in the evolution of behavioral capacity, or mind, in distantly related species (Gould, 1976; Rensch, 1959). Misunderstandings of the relation between cladistic and anagenetic approaches to the evolution of behavior should be cleared up, or at least discussed, in a chapter like this.

Following the outline just presented, this chapter has four main themes. First we review the nature of mind from a perspective that lends itself to evolutionary analysis. That perspective emphasizes a role for perceptual-motor and cognitive integration. The second theme is the hierarchical organization of very large nervous systems in effecting the integration. Third, in the light of that perspective on the nature of mind, we review the evolution of mind as the history of encephalization – the history of the enlargement of the brain beyond the grade expected from trends towards the evolution of larger bodies. Finally, we compare anagenetic with cladistic evolution in order to put the evolution of mind into an appropriate evolutionary perspective.

On mind

These are our premises: the phenomenon of mind is manifested as the ‘real’ world constructed by the brain; the quotation marks about ‘real’ are to distinguish this created world from the external world that we know exists, but which is translated into experienced reality by sensorimotor systems and by the brain. The construction of ‘reality’, discussed more fully below, is the most demanding work that the brain does, and it is primarily for this work that very large amounts of brain tissue are required. (‘Very large’, for present purposes, is of the order of 10⁷ or more nerve cells, a gram or so of human cerebral cortex, or 0.1 gram of cerebral cortex in a rat, in which neurons are packed much more densely than in the human brain; see Jerison, 1973.)

These premises about mind as a construction of the brain are fundamental hypotheses about the work of the brain and about brain/behavior relations in higher vertebrates, that is, in birds and mammals. They imply that the perceptual worlds of different species may be different, that their ‘realities’ may be different because their sensorimotor systems and brains are different. They are the bases for an analysis of mind as an evolutionary character, or trait.

Perceptual worlds

The most accessible part of the ‘reality’ that is mind is the naively known ‘real world’, the Umwelt, or perceptual world (von Uexküll, 1934). This perceptual world is related to the reality implied by physical measurement and physical theory, but a century of analysis (Carterette and Friedman, 1974) has made it clear that the physical and psychological are different worlds. Physical reality, the external world revealed by physical measurement (Bridgman, 1959), is a world we all believe exists though we do not know it directly. Experienced reality is based on that physical world, shaped by the way information about the external world is transformed at the sensory surfaces of the body and by the way that information is processed in the central nervous system. Different individuals live in different realities, depending on the nature of the transformations and processing. A color-blind person’s reality differs from that of a normal trichromat’s, for example. A classic problem in comparative psychology has been to reconstruct the perceptual worlds of other species, in which differences in sensory transformations and presumed differences further along in the central nervous system could imply fantastically different realities in different species (von Uexküll, 1934).

Some of the differences among species that have been established are, indeed, fantastic. Echolocating bats (microchiropterans), for example, apparently use auditory-vocal information to construct worlds that may be equivalent in spatial extension to our visual worlds (Griffin, 1976). These species must build their realities from time-encoded bits of information, transformed into a spatial as well as temporal world, a three-dimensional analogue, perhaps, to the picture generated by successive dots that form the image we see on a television screen. We may have a sense of how this works for a bat if we recognize something comparable that we humans do.

The finest temporal resolution of mammalian nervous systems is for the difference in the time of arrival of acoustic signals to the two ears, a difference of about 10 microseconds (Masterton and Diamond, 1973). Although demonstrated experimentally in cats and monkeys, the function is clearly the same in humans, and it functions to translate time differences into information about space rather than about time. It is the basis for the ability to localize sound in space. We humans make this transformation when we recognize the ‘where’ (rather than ‘when’) of a sound, when we localize its source in space. This can be a primary source for the construction of space by the congenitally blind. Bats may construct their ‘space’ in an analogous way, using information processed primarily by their auditory rather than visual nervous system.

The perceptual worlds of different species should be similar to the extent that they are constrained by similar physical features of the environment and are constructed by nervous systems that, at least in vertebrates, work in fundamentally similar ways. The constructed realities will, therefore, retain appropriate isomorphisms with physical reality. The realities of different species should be analogous to translations of the same ideas into different languages.

Perception, experience and consciousness

The naively known perceptual world is only part of what we would describe as mind, and we can play a kind of word game to improve our sense of the nature of mind. If we recognize the depth of the problem of knowledge, we may take ‘mind’ and ‘knowing’ as approximately synonymous. A second step can be to pair knowing with being aware (or conscious) of the experiences of the moment. The words ‘awareness’ and ‘immediate experience’ are still not quite right, but a measure of our progress in this word game is that we can be more precise about where the words are wrong. Here are a few of the problems:

First, ‘awareness’ and ‘immediate experience’ are incomplete descriptions of intuitions about mind. Careful perceptual experiments have shown that many important mental events occur without awareness (e.g. Posner, 1978), and this proves that aspects of mind other than the vague ones described in psychoanalytic practice must be unconscious. That won’t surprise many people. Second, the words are misleading. If we are serious about equating awareness with immediate experience, there is a problem with the immediacy. Experience of the moment is colored by memories and anticipations. So mind, even if restricted to immediate experience, includes expectations and memories. Developing this understanding with the help of words that make our thoughts more precise, we should also be sensitive to an important semantic problem. ‘Awareness’ and ‘experience’ are passive, and miss the manipulation and active exploration and movement that determine at least some of the work of the mind. This active dimension is important enough to be emphasized in ‘motor theories’ of consciousness (James, 1890; Sperry, 1952; cf. Held, 1965).

Language and mind

The picture of mind remains incomplete. We could add sensory dimensions: kinaesthetic, proprioceptive, gustatory, and even olfactory, beyond the visual and auditory dimensions, motor activity and expectations and memories considered thus far. Another, and major dimension of mind in the human species is linguistic. It deserves special discussion as an example of a species-typical cognitive adaptation as well as of an unusual progressive development in behavioral capacity.

Language is a double medium. When we communicate with it we use a neurobehavioral system that I believe (Jerison, 1973, 1976) evolved as a unique adaptation to contribute to the construction of ‘reality’. If I talk to you with words I send you messages that are also elements of my reality. When you hear my words you receive my messages and incorporate them into your reality. In short, when we talk we share realities. Now that is unusual for animal communication. More normal is a dog’s signaling another dog, for example, by baring its teeth. The message is a command: ‘Retreat, or face the consequences!’ There is a lack of ambiguity about the message that is rare in human communication, and to a significant extent its behavioral expression appears to be encoded in the genetic material. We communicate in this way when we blush, flinch, smile, laugh (if these are not staged) and so on. Our natural gestural ‘language’ is probably the genuine homologue of communicational systems of other species (MacLean, 1970). But when we talk (or write, or ‘sign’ with the sign languages of the deaf) we share what is on our minds. Of course, when we read we are doing some delayed sharing of the mind of the writer, and when we watch a film, all of us in attendance may live directly in the cleverly created worlds of the director, editor and actors as we experience the pleasures and pains as participant-observers. Language is a medium for sharing consciousness.

In our immediate experience of the external world we live in a created world that includes our selves as individuals. The experience has linguistic dimensions, which give it a special kind of meaning. We like to think of experience as private. Yet when we converse, or read, or watch a film we are no longer completely individual. We share the lives of others, or, more accurately, we live the lives of others, which merge with our own lives. These are not mere metaphors but state what are surely facts of mind: our minds are not limited by the boundaries of our bodies. We share the lives of others through the medium of language as if we shared information from their senses, experienced the sights they saw and the sounds they heard. In effect, we share a set of experiences that are marked by the language ‘sense’ as surely as they are marked by the conventional senses. Language enables us to share more, because we can also share more subtle experiences, such as feelings, emotions and expectations.

Mind goes beyond immediate experience and the awareness of the external world. We may achieve a better understanding than hinted at by these intuitions about language, and by the evidence on the nature of perceptual, cognitive and motor activities, if we turn now to the analysis that must take place in the brain. This is a hierarchical analysis that transforms the elementary information represented by the neural code into building blocks that are the components of the behaviors, experiences and memories, of the motoric, linguistic, perceptual and cognitive worlds that are at least components of mind.

Hierarchical structures in brain/behavior systems

Perceptual worlds may be thought of as possible worlds created by the brain to make sense of the otherwise overwhelming amount of activity of nervous systems. Our perceptual world allows a coin to be turned and moved to project changing oval and circular images on different parts of the retina, and yet there is a ‘constancy’ to the coin as an object, despite its changed stimulus configuration peripherally and the inevitably changed central neural events generated by the peripheral image.

This is the work involved in the construction of Umwelten. It is costly neural activity in that much neural machinery is used to build these worlds, which maintain their constant structure and also reflect changing events within the structure. The construction should be thought of as occurring at certain levels of the hierarchical organization of the brain’s work. At lower levels it is the work of single neurons and then of relatively small networks of neurons. The work at one level may be described with a different vocabulary from the work at another level. Lower level work might be described with the language of cellular neurophysiology, and higher level work with the language of nerve networks and neural systems.

Like all large information processing systems, whether artificial or natural, large brains must function hierarchically (Simon, 1974). The elements of neural information, which are changes of state in individual nerve cells, must be combined or chunked into subroutines within higher order programs, and it is the higher order programs that actually control behavior and experience.

Physiological hierarchies

Important transformations change the information available to and used by living organisms, and the sequence of changes takes place at successive levels of organization. Environmental information is in the form of physical energy: photons, the movement of molecules of air, chemicals that can reach sensory surfaces, the mechanical deformation of the skin, inertial changes in body fluids, and so on. Such information is transformed by sense cells into neural events in peripheral parts of the visual, auditory, olfactory and gustatory (chemical), tactile, and proprioceptive systems. Other information, feedback from body tissues, is relayed by peripheral parts of the kinaesthetic and autonomic nervous systems. At this stage of information processing, very different kinds of...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Notes on the contributors
• Editor’s introduction
• Human brain anatomy
• 1 On the evolution of mind: Harry J. Jerison
• 2 Representations of the physical and social world: Keith Oat ley
• 3 Is consciousness the gateway to the hippocampal cognitive map? A speculative essay on the neural basis of mind: John O’Keefe
• 4 Cognition and imagery in animals: David A. Oakley
• 5 Animal awareness, consciousness and self-image: David A. Oakley
• 6 Neuropsychology of consciousness: a review of human clinical evidence: Freda Newcombe
• 7 Brain, mind and language: Joseph E. LeDoux
• 8 The plurality of consciousness: David A. Oakley and Lesley C. Eames
• Name index
• Subject index